The present invention relates to a diaphragm carburetor for an internal combustion engine having a manual starter, wherein the diaphragm comprises a fuel-filled control chamber that is connected by a main valve path to a venturi section of the suction channel and is connected by an idle valve path which, in the flow direction of the combustion air, opens via at least one idle valve downstream of a rotatably supported throttle flap into the suction channel. A choke flap is positioned upstream of the venturi section, when viewed in the flow direction of the combustion air, in the suction channel and is rotatable for enriching the fuel/air mixture for cold start as well as warm start conditions of the combustion engine.
Such a diaphragm carburetor is known from German Patent Application 41 20 876 and is provided with a starter for cold start and warm start of the engine. In the suction channel of the diaphragm carburetor a venturi section is provided which in the flow direction of the combustion air has positioned upstream thereof a choke flap and downstream thereof a throttle flap. The starter closes the choke flap completely during cold start conditions with the exception of a bypass opening. For warm start conditions the choke flap is positioned in a partly open position. In both start positions, the operator must ensure that upon startup of the combustion engine the choke flap is immediately opened so that the fuel/air mixture will not become too rich causing the engine to die.
It is therefore an object of the present invention to embody a diaphragm carburetor of the aforementioned kind such that without actions by the operator the combustion engine after startup continues to run with the choke flap being in the closed position.